This invention relates to personal cleansing products which include mid-chain branched surfactants.
The developer and formulator of surfactants for personal cleansing detergents must consider a wide variety of possibilities with limited (sometimes inconsistent) information, and then strive to provide overall improvements in one or more of a whole array of criteria, including performance in the presence of free calcium, in complex mixtures of surfactants and polymers, formulation changes including silicone conditioners, enzyme, various changes in consumer habits and practices, and the need for biodegradability. Furthermore, personal cleansing detergents should also employ materials that enhance product phase stability at low temperatures. Lack of phase stability can lead to unacceptable Theological and aesthetic properties as well as to performance issues. Such low temperatures can be encountered in warehouses, in the consumer""s garage, in the consumer""s automobile, during street vending, on a cold bathroom window sill, and the like.
Further, personal cleansing compositions should employ materials that enhance the dissolution, or rate of product mixing, with water. Further, personal cleansing detergents should employ materials that enhance the tolerance of the system to hardness, especially to avoid the precipitation of the calcium salts of anionic surfactants. Precipitation of the calcium salts of anionic surfactants is known to cause suppression of suds, irritation to the skin, and can lead to an undesirable hair feel. The lack of tolerance to low temperature and hardness prevents widespread use of personal cleansing products in which sodium alkyl sulfate is the only anionic surfactant.
The development of improved surfactants for use in personal cleansing compositions is clearly a complex challenge.
It is an aspect of the present invention to provide mixtures of the mid-chain branched primary alkyl surfactants which are formulatable with other surfactants to provide personal cleansing compositions having one or more advantages, including greater product stability at low temperatures, increased resistance to water hardness, greater efficacy in surfactant systems, improved removal of greasy or particulate body soils, lower deposition levels on the hair and skin with subsequent improvement in feel and mildness, and the like.
U.S. Pat. No. 3,480,556, EP 439,316, EP 684,300, EP 439,316, U.S. Pat. No. 3,480,556, R. G. Laughlin in xe2x80x9cThe Aqueous Phase Behavior of Surfactantsxe2x80x9d, Academic Press, N.Y. (1994), Finger et al., xe2x80x9cDetergent alcoholsxe2x80x94the effect of alcohol structure and molecular weight on surfactant propertiesxe2x80x9d, J Amer. Oil Chemists"" Society, Vol. 44, Technical Bulletin, Shell Chemical Co., SC: 364-80, EP 342,917 A, U.S. Pat. No. 4,102,823, GB 1,399,966, G.B. Patent 1,299,966, EP 401,462 A, K. R. Wormuth and S. Zushma, Langmuir, Vol. 7, (1991), pp 2048-2053, R. Varadaraj et al., J. Phys. Chem., Vol. 95, (1991), pp 1671-1676, Varadtraj et al., J. Colloid and terface Sci., Vol. 140, (1990), pp 31-34, Varadaraj7 et al., Langmuir, Vol. 6 (1990), pp 1376-1378, U.S. Pat. No. 5,284,989, U.S. Pat. No. 5,026,933, U.S. Pat. No. 4,870,038, Surfactant Science Series, Marcel Dekker, N.Y., CEH Marketing Research Report xe2x80x9cDetergent Alcoholsxe2x80x9d by R. F. Modler et al., Chemical Economics Handbook, 1993, 609.5000-609.5002; Kirk Qtllmer""s Encyclopedia of Chemical Technology, 4th Edition, Wiley, New York, 1991, xe2x80x9cAlcohols, Higher Aliphaticxe2x80x9d in Vol. 1, pp 865-913 and references therein.
The present invention provides a personal cleansing compositions comprising a mid-chain branched surfactants and a conventional personal cleansing adjutant.
Specifically, the present invention comprises a personal cleansing composition comprising:
i) from about 0.001% to about 49.9% by weight of a conventional personal cleansing additive;
ii) from a bout 0.1% to about 49.999% by weight of a surfactant system comprising a branched surfactant mixture, said branched surfactant mixture comprising mid-chain branched and linear surfactant compounds, said linear compounds less than about 25% by weight of the branched surfactant., mixture;
wherein the mid-chain branched surfactant compounds are of the formula:
xe2x80x83Abxe2x88x92B
xe2x80x83wherein:
Ab is a hydrophobic moiety having from about 10 to about 18 total carbons divided between a longest chain and at least one short chain, the longest chain being in the range of from about 9 to about 17 carbon atoms, there being one or more C1-C3 alkyl moieties branching from the longest chain, provided that at least one of the branching alkyl moieties is attached directly to a carbon of the longest linear carbon chain at a position within the range of position 3 carbon, counting from carbon #1 which is attached to the xe2x80x94B moiety, to position xcfx89xe2x80x942 carbon, wherein co is the terminal carbon;
B is a hydrophilic moiety selected from the group consisting of OSO3M, (EO/PO)mOH, EO/PO)mOSO3M and mixtures thereof, wherein EO/PO are alkoxy moieties selected from the group consisting of ethoxy, propoxy, and mixtures thereof, wherein m is at least about 1 to about 30 and M is hydrogen or a salt forming cation;
provided that the average total number of carbon atoms in the Ab moiety in the branched surfactant mixture is within the range of about 12 to 14.5; and
(iii) from about 50% to about 99.899%, by weight of an aqueous liquid carrier.
In a second embodiment the present invention also includes an antidandruff shampoo comprising a branched surfactant system, hereinbefore defined; from about 0.1% to about 5% by weight of an antidandruff agent selected from the group consisting of type (a), type (b), both of are defined hereinafter, and mixtures thereof; and from about 50% to about 99.89%, by weight of an aqueous liquid carrier;
In a third embodiment the present invention also includes a personal cleansing composition comprising a branched surfactant system, hereinbefore defined; from about 0.005% to about 20% by weight of a conditioning agent selected from the group consisting of nonvolatile hydrocarbon conditioning agents. nonvolatile silicone conditioning agents and mixtures thereof; from about 50% to about 99.89%, by weight of an aqueous liquid carrier; and from about 0.1% to about 10%, by weight of a suspending agent.
In a fourth embodiment the present invention also includes a personal cleansing composition comprising a branched surfactant system, hereinbefore defined; from about 0.1% to about 10% by weight of a water insoluble hair styling polymer; from about 50% to about 99.849%, by weight of an aqueous liquid carrier; and from about 0.1% to about 10%, by weight of a volatile water insoluble solvent.
In a fifth embodiment the present invention also includes a personal cleansing composition comprising a branched surfactant system, hereinbefore defined; from about 0.01% to about 5% by weight of a deposition polymer; and from about 50% to about 99.89%, by weight of an aqueous liquid carrier;
In a sixth embodiment the present invention also includes a personal cleansing composition comprising a branched surfactant system, hereinbefore defined; from about 0.1% to about 10% by weight of a dispersed phase polymer; and from about 50% to about 99.89%, by weight of an aqueous liquid carrier;
In a seventh embodiment the present invention also includes a method of treating hair by administering a safe and effective amount of a personal cleansing composition as hereinbefore defined.
In an eight embodiment the present invention also includes a method of treating skin by administering a safe and effective amount of a personal cleansing composition as hereinbefore defined.
In a ninth embodiment the present invention also includes a method of cleaning hair and skin by administering a safe and effective amount of a personal cleansing composition as hereinbefore defined.
These and other aspects, features and advantages will be apparent from the following description and the appended claims.
All percentages, ratios and proportions herein are on a weight basis unless otherwise indicated. All documents cited herein are hereby incorporated herein by reference.
The personal cleansing compositions of this invention comprise a surfactant-containing, preferably surfactant-structured liquid phase which comprises a branched surfactant mixture comprising linear and mid-chain branched surfactants. The essential and optional components of the surfactant mixture and other optional materials of the detergent compositions herein, as well as composition form, preparation and use, are described in greater detail as follows: (All concentrations and ratios are on a weight basis unless otherwise specified.)
Specifically, the present invention comprises a personal cleansing composition The personal cleansing composition comprises:
i) from about 0.001% to about 49.9%, by weight of a conventional personal cleansing additive;
ii) from about 0.1% to about 49.999% by weight of a surfactant system comprising a branched surfactant mixture, said branched surfactant mixture comprising mid-chain branched and linear surfactant compounds, said linear compounds comprising 25% or less by weight of the branched surfactant mixture;
wherein the mid-chain branched surfactant compounds are of the formnula:
Abxe2x88x92B
xe2x80x83wherein:
Ab is a hydrophobic moiety having from about 10 to about 18 total carbons divided between a longest chain and at least one short chain, the longest chain being in the range of from about 9 to about 17 carbon atoms, there being one or more C1-C3 alkyl moieties branching from the longest chain, provided that at least one of the branching alkyl moieties is attached directly to a carbon of the longest linear carbon chain at a position within the range of position 3 carbon, counting from carbon #1 which is attached to thexe2x80x94B moiety, to position xcfx89xe2x80x942 carbon, wherein xcfx89 is the terminal carbon;
B is a hydrophilic moiety selected from the group consisting of OSO3M, (EO/PO)mOH, (EO/PO)mOSO3M and mixtures thereof, wherein EO/PO are alkoxy moieties selected from the group consisting of ethoxy, propoxy, and mixtures thereof, wherein m is at least about 1 to about 30 and M is hydrogen or a salt forming cation;
provided that the average total number of carbon atoms in the Ab moiety in the branched surfactant mixture is within the range of about 12 to 14.5; and
(iii) from about 50% to about 99.899%, by weight of an aqueous liquid carrier.
The detergent compositions defined herein comprises from about 0.01% to about 49.999% by weight of the surfactant system. The surfactant system will be present in the personal cleansing composition at preferably at least about 0.5%, more preferably, at least about 1%, even more preferably at least about 2%, even more preferably still at least about 5%, even more preferably still at least about 8%, most preferably at least about 10%, by weight. Furthermore, the surfactant system will be; present in the personal cleansing composition at preferably at less than about 45%, more preferably less than about 45%, even more preferably less than about 40%, even more preferably less than about 35%, even more preferably less than about 30%, by weight.
Ab moiety has from about 10 to about 18, preferably from about 11 to about 17, most preferably from about 11 to about 15 carbon atoms. The average total number of carbon atoms in the Ab moiety in the branched surfactant mixture defined above should be within the range of from about 12 to 14.5, preferably from about 12 to about 14 and most preferably from about 12 to about 13.5. The xe2x80x9ctotalxe2x80x9d number of carbon atoms as used herein is intended to mean the number of carbon atoms in the longest chain, i.e. the backbone of the molecule, plus the number of carbon atoms in all of the short chains, i.e. the branches.
The detergent compositions defined herein also comprise from about 0.001% to about 49.9% by weight of the composition of a conventional personal cleansing additive. The conventional personal cleansing additive will be present in the personal cleansing composition at preferably at least about 0.5%, more preferably, at least about 1%, even more preferably at least about 2%, even more preferably still at least about 5%, even more preferably still at least about 8%, most preferably at least about 10%, by weight. Furthermore, the conventional personal cleansing additive will be present in the personal cleansing composition at preferably at less than about 45%, more preferably less than about 40%, even more preferably less than about 35%, even more preferably less than about 30%, even more preferably less than about 20%, most preferably less than about 15%, by weight. This conventional personal cleansing additive is selected from the group comprising conditioning agents, conventional personal care polymers, antidandruff agents co-surfactants and mixtures thereof, all of which are hereinafter defined.
The aqueous liquid carrier is present in the personal cleansing composition from about 50% to about 99.899%, preferably about 60% to about 95%, more preferably about 70% to about 85% by weight.
The linear surfactant compounds present in the branched surfactant mixture comprise 25% or less preferably about 20% or less, more preferably about 15% or less even more preferably about 10% or less and even more preferably still about 5% or less by weight of the surfactant mixture.
The personal cleansing composition of the present invention is in the form of a liquid or a liquid gel. It can contain for example, suspended ingredients, more than one phase etc. Effectively the personal cleansing compositions of the present invention can be in the form of any type of liquid or liquid gel and contain any additive conventionally added to personal cleansing compositions, such as shampoos, body wash gels, bath gels etc.
The branched surfactants for use in the personal cleansing compositions of the present invention can preferably comprise compounds of the above formula wherein the Ab moiety is a branched alkyl moiety having the formula: 
wherein the total number of carbon atoms in the branched alkyl moiety of this formula, including the R, R1, and R2 branching, is from 8 to 18; R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl, preferably methyl, provided R, R1, and R2 are not all hydrogen and, when z is 0, at least R or R1 is not lhydrogen; w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10 land w+x+y+z is from 2 to 10.
Moreover, an especially preferred branched surfactant for use in the personal cleansing compositions of the present invention comprises an Ab moiety which is characterized as having one of the two formulas below and mixtures thereof: 
or mixtures thereof; wherein a, b, d, and e are integers, a+b is from 6 to 13, d+e is from 4 to 11 and wherein further
when a+b=6, a is an integer from 2 to 5 and b is an integer from 1 to 4;
when a+b=7, a is an integer from 2 to 6 and b is an integer from 1 to 5;
when a+b=8, a is an integer from 2 to 7 and b is an integer from 1 to 6;
when a+b=9, a is an integer from 2 to 8 and b is an integer from 1 to 7;
when a+b=10, a is an integer from 2 to 9 and b is an integer from 1 to 8;
when a+b=11, a is an integer from 2 to 10 and b is an integer from 1 to 9;
when a+b=12, a is an integer from 2 to 11 and b is an integer from 1 to 10;
when a+b=13, a is an integer from 2 to 12 and b is an integer from 1 to 11;
when d+e=4, d is an integer from 2 to 3 and e is an integer from 1 to 2;
when d+e=5, d is an integer from 2 to 4 and e is an integer from 1 to 3;
when d+e=6, d is an integer from 2 to 5 and e is an integer from 1 to 4;
when d+e=7, d is an integer from 2 to 6 and e is an integer from 1 to 5;
when d+e=8, d is an integer from 2 to 7 and e is an integer from 1 to 6;
when d+e=9, d is an integer from 2 to 8 and e is an integer from 1 to 7;
when d+e=10, d is an integer from 2 to 9 and e is an integer from 1 to 8.
when d+e=11, d is an integer from 2 to 10 and e is an integer from 1 to 9.
(1) Midhain Branched Primary Alkyl Sulfate Surfactants
The mid-chain branched surfactant system for use in the personal cleansing compositions of the present invention may comprise one or more mid-chain branched primary alkyl sulfate surfactants having the formula: 
More specifically, the branched surfactant mixtures of the present invention comprise molecules having a linear primary alkyl sulfate chain backbone (i.e., the longest linear carbon chain which includes the sulfated carbon atom). These alkyl chain backbones comprise from about 10 to about 18 carbon atoms; and further the molecules comprise a branched primary alkyl moiety or moieties having at least about 1, but not more than 3, carbon atoms. In addition, the surfactant mixture has an average total number of carbon atoms for the branched primary alkyl moieties of less than 14.5, preferably within the range of from about 12 to 14.5. Thus, the present invention mixtures comprise at least one branched primary alkyl sulfate surfactant compound having a longest linear carbon chain of not less than 9 carbon atoms or more than 17 carbon atoms, and the average total number of carbon atoms for the branched primary alkyl chains is within the range of about 12 to 14.5, preferably from about 12 to about 14 and most preferably from about 12 to about 13.5.
For example, a C14 total carbon primary alkyl sulfate surfactant having 11 carbon atoms in the backbone must have 1, 2, or 3 branching units (i.e., R, R1 and/or R2) whereby total number of carbon atoms in the molecule is 14. In this example, the C14 total carbon requirement may be satisfied equally by having, for example, one propyl branching unit or three methyl branching units.
R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl (preferably hydrogen or C1-C2 alkyl, more preferably hydrogen or methyl, and most preferably methyl), provided R, R1, and R2 are not all hydrogen. Further, when z is 0, at least R or R1 is not hydrogen.
Although for the purposes of the present invention the surfactant systems of the above formula do not include molecules wherein the units R, R1, and R2 are all hydrogen (i.e., linear non-branched primary alkyl sulfates), it is to be recognized that the present surfactant systems may still further comprise some amount of linear, non-branched primary alkyl sulfate. Further, this linear non-branched primary alkyl sulfate surfactant may be present as the result of the process used to manufacture the surfactant mixture having the requisite one or more mid-chain branched primary alkyl sulfates according to the present invention, or for purposes of formulating personal cleansing compositions some amount of linear non-branched primary alkyl sulfate may be admixed into the final product formulation.
Further it is to be similarly recognized that non-sulfated mid-chain branched alcohol may comprise some amount of the present surfactant system. Such materials may be present as the result of incomplete sulfation of the alcohol used to prepare the alkyl sulfate surfactant, or these alcohols may be separately added to the present personal cleansing compositions along with a mid-chain branched alkyl sulfate surfactant according to the present invention.
M is hydrogen or a salt forming cation depending upon the method of synthesis. Examples of salt forming cations are lithium, sodium, potassium, calcium, magnesium, quaternary alkyl amines having the formula 
wherein R3, R4, R5 and R6 are independently hydrogen, C1-C22 alkylene, C4-C22 branched alkylene, C1-C6 alkanol, C1-C22 alkenylene, C4-C22 branched alkenylene, and mixtures thereof. Preferred cations are ammonium (R3, R4, R5 and R6 equal hydrogen), sodium, potassium, mono-, di-, and trialkanol ammonium, and mixtures thereof. The monoalkanol ammonium compounds of the present invention have R3 equal to C1-C6 alkanol, R4, R5 and R6 equal to hydrogen; dialkanol ammonium compounds of the present invention have R3 and R4 equal to C1-C6 alkanol, R5 and R6 equal to hydrogen; trialkanol ammonium compounds of the present invention have R3, R4 and R5 equal to C1-C6 alkanol, R6 equal to hydrogen. Preferred alkanol ammonium salts of the present invention are the mono-, di- and tri-quaternary ammonium compounds having the formulas: H3N+CH2CH2OH, H2N+(CH2CH2OH)2, HN+(CH2CH2OH)3. Preferred M is sodium, potassium and the C2 alkanol ammonium salts listed above; the most M preferred is sodium.
Further regarding the above formula, w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10; and w+x+y+z is an integer from 3 to 11.
The preferred surfactant system will be present in the personal cleansing composition at preferably at least about 0.5%, more preferably, at least about 1%, even more preferably at least about 2%, even more preferably still at least about 5%, even more preferably still at least about 8%, most preferably at least about 10%, by weight. Furthermore, the preferred surfactant mixture will be present in the personal cleansing composition at preferably at less than about 45%, more preferably less than about 40%, even more preferably less than about 35%, even more preferably less than about 30%, by weight. 
wherein the total number of carbon atoms, including branching, is from 10 to 16, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of from about 12 to about 14; R1 and R2 are each independently hydrogen or A C1-C3 alkyl; M is a water soluble cation; x is from 0 to 10; y is from 0 to 10; z is from 0 to 10 and x+y+z is from 4 to 10; provided R1 and R2 are not both hydrogen. More preferred are compositions having at least 5% of the mixture comprising one or more mid-chain branched primary alkyl sulfates wherein x+y is equal to 6 and z is at least 1.
Preferably, the mixtures of surfactant comprise at least 5% of a mid chain branched primary alkyl sulfate having R1 and R2 independently hydrogen, methyl, provided R1 and R2 are not both hydrogen; x+y is equal to 5, 6 or 7 and z is at least 1. More preferably the mixtures of surfactant comprise at least 20% of a mid chain branched primary alkyl sulfate having R1 and R2 independently hydrogen or methyl, provided R1 and R2 are not both hydrogen; x+y is equal to 5, 6 or 7 and z is at least 1.
Preferred mid-chain branched primary alkyl sulfate surfactants for use in the personal cleansing compositions defined herein are selected from the group of compounds having the formula: 
and mixtures thereof; wherein M represents one or more cations; and mixtures thereof, wherein a, b, d, and e are integers, a+b is from 6 to 13, d+e is from 4 to 11 and wherein further
when a+b=6, a is an integer from 2 to 5 and b is an integer from 1 to 4;
when a+b=7, a is an integer from 2 to 6 and b is an integer from 1 to 5;
when a+b=8, a is an integer from 2 to 7 and b is an integer from 1 to 6;
when a+b=9, a is an integer from 2 to 8 and b is an integer from 1 to 7;
when a+b=10, a is an integer from 2 to 9 and b is an integer from 1 to 8;
when a+b=11, a is an integer from 2 to 10 and b is an integer from 1 to 9;
when a+b=12, a is an integer from 2 to 11 and b is an integer from 1 to 10;
when a+b=13, a is an integer from 2 to 12 and b is an integer from 1 to 11;
when d+e=4, d is an integer from 2 to 3 and e is an integer from 1 to 2;
when d+e=5, d is an integer from 2 to 4 and e is an integer from 1 to 3;
when d+e=6, d is an integer from 2 to 5 and e is an integer from 1 to 4;
when d+e=7, d is an integer from 2 to 6 and e is an integer from 1 to 5;
when d+e=8, d is an integer from 2 to 7 and e is an integer from 1 to 6;
when d+e=9, d is an integer from 2 to 8 and e is an integer from 1 to 7;
when d+e=10, d is an integer from 2 to 9 and e is an integer from 1 to 8.
when d+e=11, d is an integer from 2 to 10 and e is an integer from 1 to 9.
Wherein the average total number of carbon atoms in the branched primary alkyl moieties having the above formulas is within the range of about 12 to 14.5. Especially preferred mid-chain branched surfactants are those comprising a mixture of compounds having the general formulas from Groups I and II, wherein the molar ratio of compounds according to Group I to Group II is greater than about 4:1, preferably greater than about 9:1 and most preferably greater than about 20:1.
Further, the present surfactant systems may comprise a mixture of linear and branched surfactants wherein the branched primary alkyl sulfates have the formula 
wherein the total number of carbon atoms per molecule, including branching, is from 10 to 17, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of about 12 to 14.5; R, R1, and R2 are each, independently selected from hydrogen and C1-C3 alkyl, provided R, R1, and R2 are not all hydrogen; M is a water soluble cation; w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10; and w+x+y+z is from 3 to 10; provided that when R2 is a C1-C3 alkyl the ratio of surfactants having z equal to 1 or greater to surfactants having z of 0 is at least about 1:1, preferably at least about 5:1, more preferably at least about 10:1, and most preferably at least about 20:1. Also preferred are surfactant compositions, when R2 is a C1-C3 alkyl, comprising less than about 20%, preferably less than 10%, more preferably less than 5%, most preferably less than 1%, of branched primary alkyl sulfates having the above formula wherein z equals 0.
Preferred mono methyl branched primary alkyl sulfates selected from the group consisting of: 3-methyl undecanol sulfate, 4-methyl undecanol sulfate, 5-methyl undecanol sulfate, 6-methyl undecanol sulfate, 7-methyl undecanol sulfate, 8-methyl undecanol sulfate, 9-methyl undecanol sulfate, 3-methyl dodecanol sulfate, 4-methyl dodecanol sulfate, 5-methyl dodecanol sulfate, 6-methyl dodecanol sulfate, 7-methyl dodecanol sulfate, 8-methyl dodecanol sulfate, 9-methyl dodecanol sulfate, 10-methyl dodecanol sulfate, 3-methyl tridecanol sulfate, 4-methyl tridecanol sulfate, 5-methyl tridecanol sulfate, 6-methyl tridecanol sulfate, 7-methyl tridecanol sulfate, 8-methyl tridecanol sulfate, 9-methyl tridecanol sulfate, 10-methyl tridecanol sulfate, 11-methyl tridecanol sulfate, and mixtures thereof.
Preferred dimethyl branched primary alkyl sulfates are selected from the group consisting of: 2,3-dimethyl undecanol sulfate, 2,4-dimethyl undecanol sulfate, 2,5-dimethyl undecanol sulfate, 2,6-dimethyl undecanol sulfate, 2,7-dimethyl undecanol sulfate, 2,8-dimethyl undecanol sulfate, 2,9-dimethyl undecanol sulfate, 2,3-dimethyl dodecanol sulfate, 2,4-dimethyl dodecanol sulfate, 2,5-dimethyl dodecanol sulfate, 2,6dimethyl dodecanol sulfate, 2,7-dimethyl dodecanol sulfate, 2,8-dimethyl dodecanol sulfate, 2,9-dimethyl dodecanol sulfate, 2,10-dimethyl dodecanol sulfate, and mixtures thereof.
The following branched primary alkyl sulfates comprising 13 carbon atoms and having one branching unit are examples of preferred branched surfactants useful in the present invention compositions: 
wherein M is preferably sodium.
The following branched primary alkyl sulfates comprising 14 carbon atoms and having two branching units are examples of preferred branched surfactants according to the present invention: 
wherein M is preferably sodium.
(2) Mid-chain Branched Primary Alkly Alkoxylated Sulfate Surfactants
The mid-chain branched surfactant system for use in the personal cleansing compositions of the present invention may comprise one or more (preferably a mixture of two or more) mid-chain branched primary alkyl alkoxylated sulfates having the formula: 
The surfactant mixtures of the present invention comprise molecules having a linear primary alkoxylated sulfate chain backbone (i.e., the longest linear carbon chain which includes the alkoxy-sulfated carbon atom). These alkyl chain backbones comprise from about 10 to about 18 carbon atoms; and further the molecules comprise a branched primary alkyl moiety or moieties having at least about 1, but not more than 3, carbon atoms. In addition, the surfactant mixture has an average total number of carbon atoms for the branched primary alkyl moieties of less than 14.5, preferably within the range of from about 12 to 14.5. Thus, the present invention mixtures comprise at least one branched primary alkyl sulfate surfactant compound having a longest linear carbon chain of not less than 9 carbon atoms or more than 17 carbon atoms, and the average total number of carbon atoms for the branched primary alkyl chains is within the range of from about 12 to 14.5, preferably from about 12 to about 14 and most preferably from about 12 to about 13.5.
For example, a C14 total carbon primary alkyl sulfate surfactant having 11 carbon atoms in the backbone must have 1, 2, or 3 branching units (i.e., R, R1 and/or R2) whereby total number of carbon atoms in the alkyl moiety is 14. In this example, the C14 total carbon requirement may be satisfied equally by having, for example, one propyl branching unit or three methyl branching units.
R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl (preferably hydrogen or C1-C2 alkyl, more preferably hydrogen or methyl, and most preferably methyl), provided R, R1, and R2 are not all hydrogen. Further, when z is 0, at least R or R1 is not hydrogen.
Although for the purposes of the present invention the surfactant systems according to the above formula do not include molecules wherein the units R, R1, and R2 are all hydrogen (i.e., linear non-branched primary alkoxylated sulfates), it is to be recognized that the present surfactant system may still further comprise some amount of linear, non-branched primary alkoxylated sulfate. Further, this linear non-branched primary alkoxylated sulfate surfactant may be present as the result of the process used to manufacture the surfactant mixture having the requisite mid-chain branched primary alkoxylated sulfates according to the present invention, or for purposes of formulating personal cleansing compositions some amount of linear to non-branched primary alkoxylated sulfate may be admixed into the final product formulation.
It is also to be recognized that some amount of mid-chain branched alkyl sulfate may be present in the surfactant system. This is typically the result of sulfation of non-alkoxylated alcohol remaining following incomplete alkoxylation of the mid-chain branched alcohol used to prepare the alkoxylated sulfate useful herein. It is to be recognized, however, that separate addition of such mid-chain branched alkyl sulfates is also contemplated by the present personal cleansing compositions.
Further it is to be similarly recognized that non-sulfated mid-chain branched alcohol (including polyoxyalkylene alcohols) may comprise some amount of the present invention alkoxylated sulfate-containing surfactant systems. Such materials may be present as the result of incomplete sulfation of the alcohol (alkoxylated or non-alkoxylated) used to prepare the alkoxylated sulfate surfactant, or these alcohols may be separately added to the present personal cleansing compositions along with a mid-chain branched alkoxylated sulfate surfactant according to the present invention.
M is as described hereinbefore.
Further regarding the above formula, w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10; and w+x+y+z is an integer from 3to 10.
EO/PO are alkoxy moieties, preferably selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 0.01, preferably within the range of from about 0.1 to about 30, more preferably from about 0.5 to about 10, and most preferably from about 1 to about 5. The (EO/PO)m moiety may be either a distribution with average degree of alkoxylation (e.g., ethoxylation and/or propoxylation) corresponding to m, or it may be a single specific chain with alkoxylation (e.g., ethoxylation and/or propoxylation) of exactly the number of units corresponding to m.
The preferred surfactant system will be present in the personal cleansing composition at preferably at least about 0.5%, more preferably, at least about 1%, even more preferably at least about 2%, even more preferably still at least about 5%, even more preferably still at least about 8%, most preferably at least about 10%, by weight. Furthermore, the preferred surfactant mixture will be present in the personal cleansing composition at preferably at less than about 45%, more preferably less than about 40%, even more preferably less than about 35%, even more preferably less than about 30%, by weight of the mixture one or more branched primary alkyl alkoxylated sulfates having the formula 
wherein the total number of carbon atoms, including branching, is from 10 to 16, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of from about 12 to about 14; R1 and R2 are each independently hydrogen or C1-C3 alkyl; M is a water soluble cation; x is from 0 to 10; y is from 0 to 10; z is from 0 to 10 and x+y+z is from 4 to 10; provided R1 and R2 are not both hydrogen and EO/PO are alkoxy moieties selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 0.01, preferably within the range of from about 0.1 to about 30, more preferably from about 0.5 to about 10, and most preferably from about 1 to about 5. More preferred are compositions having at least 5% of the mixture comprising one or more mid-chain branched primary alkyl alkoxy sulfates wherein x+y is equal to 6 and z is at least 1.
Preferably, the mixtures of surfactant comprise at least 5% of a mid chain branched primary alkyl sulfate having R1 and R2 independently hydrogen, methyl, provided R1 and R2 are not both hydrogen; x+y is equal to 5, 6 or 7 and z is at least 1. More preferably the mixtures of surfactant comprise at least 20% of a mid chain branched primary alkyl sulfate having R1 and R2 independently hydrogen or methyl, provided R1 and R2 are not both hydrogen; x+y is equal to 5, 6 or 7 and z is at least 1.
Preferred mixtures of mid-chain branched primary alkyl alkoxylated sulfate and linear alkyl alkoxylated sulfate surfactants comprise at least about 5% by weight of one or more mid-chain branched alkyl alkoxylated sulfates having the formula: 
and mixtures thereof M represents one or more cations. a, b, d, and e are integers, a+b is from 6 to 13, d+e is from 4 to 11 and wherein further
when a+b=6, a is an integer from 2 to 5 and b is an integer from 1 to 4;
when a+b=7, a is an integer from 2 to 6 and b is an integer from 1 to 5;
when a+b=8, a is an integer from 2 to 7 and b is an integer from 1 to 6;
when a+b=9, a is an integer from 2 to 8 and b is an integer from 1 to 7;
when a+b=10, a is an integer from 2 to 9 and b is an integer from 1 to 8;
when a+b=11, a is an integer from 2 to 10 and b is an integer from 1 to 9;
when a+b=12, a is an integer from 2 to 11 and b is an integer from 1 to 10;
when a+b=13, a is an integer from 2 to 12 and b is an integer from 1 to 11;
when d+e=4, d is an integer from 2 to 3 and e is an integer from 1 to 2;
when d+e=5, d is an integer from 2 to 4 and e is an integer from 1 to 3;
when d+e=6, d is an integer from 2 to 5 and e is an integer from 1 to 4;
when d+e=7, d is an integer from 2 to 6 and e is an integer from 1 to 5;
when d+e=8, d is an integer from 2 to 7 and e is an integer from 1 to 6;
when d+e=9, d is an integer from 2 to 8 and e is an integer from 1 to 7;
when d+e=10, d is an integer from 2 to 9 and e is an integer from 1 to 8.
when d+e=11, d is an integer from 2 to 10 and e is an integer from 1 to 9.
The average total number of carbon atoms in the branched primary alkyl moieties having the above formulas is within the range of about 12 to 14.5 and EO/PO are alkoxy moieties selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 0.01, preferably within the range of from about 0.1 to about 30, more preferably from about 0.5 to about 10, and most preferably from about 1 to about 5. Especially preferred mid-chain branched surfactants are those comprising a mixture of compounds having the general formulas from Groups I and II, wherein the molar ratio of compounds according to Group I to Group II is greater than about 4:1, preferably greater than about 9:1 and most preferably greater than about 20:1.
Further, the present surfactant systems may comprise a mixture of linear and branched surfactants wherein the branched primary alkyl alkoxylated sulfates has the formula: 
wherein the total number of carbon atoms per molecule, including branching, is from 10 to 17, and wherein further for th is surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of about 12 to 14.5; R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl, provided R, R1, and R2 are not all hydrogen; M is a water soluble cation; w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10; and w+x+y+z is from 3 to 10; EO/PO are alkoxy moieties, preferably selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 0.01, preferably within the range of from about 0.1 to about 30, more preferably from about 0.5 to about 10, and most preferably from about 1 to about 5; provided that when R2 is a C1-C3 alkyl the ratio of surfactants having z equal to 1 or greater to surfactants having z of 0 is at least about 1:1, preferably at least about 5:1, more preferably at least about 10:1, and most preferably at least about 20:1. Also preferred are surfactant compositions, when R2 is a C1-C3 alkyl, comprising less than about 20%, preferably less than 10%, more preferably less than 5%, most preferably less than 1%, of branched primary alkyl alkoxylated sulfate having the above formula wherein z equals 0.
Preferred mono-methyl branched primary alkyl ethoxylated sulfates are selected from the group consisting of: 3-methyl dodecanol ethoxylated sulfate, 4-methyl dodecanol ethoxylated sulfate, 5-methyl dodecanol ethoxylated sulfate, 6-methyl dodecanol ethoxylated sulfate, 7-methyl dodecanol ethoxylated sulfate, 8-methyl dodecanol ethoxylated sulfate, 9-methyl dodecanol ethoxylated sulfate, 10-methyl dodecanol ethoxylated sulfate, 3-methyl tridecanol ethoxylated sulfate, 4-methyl tridecanol ethoxylated sulfate, 5-methyl tridecanol ethoxylated sulfate, 6-methyl tridecanol ethoxylated sulfate, 7-methyl tridecanol ethoxylated sulfate, 8-methyl tridecanol ethoxylated sulfate, 9-methyl tridecanol ethoxylated sulfate, 10-methyl tridecanol ethoxylated sulfate, 11-methyl tridecanol ethoxylated sulfate, and mixtures thereof, wherein the compounds are ethoxylated with an average degree of ethoxylation of from about 0.1 to about 10.
Preferred dimethyl branched primary alkyl ethoxylated sulfates selected from the group consisting of: 2,3-dimethyl undecanol ethoxylated sulfate, 2,4-dimethyl undecanol ethoxylated sulfate, 2,5-dimethyl undecanol ethoxylated sulfate, 2,6-dimethyl undecanol ethoxylated sulfate, 2,7-dimethyl undecanol ethoxylated sulfate, 2,8-dimethyl undecanol ethoxylated sulfate, 2,9-dimethyl undecanol ethoxylated sulfate, 2,3-dimethyl dodecanol ethoxylated sulfate, 2,4-dimethyl dodecanol ethoxylated sulfate, 2,5-dimethyl dodecanol ethoxylated sulfate, 2,6-dimethyl dodecanol ethoxylated sulfate, 2,7-dimethyl dodecanol ethoxylated sulfate, 2,8-dimethyl dodecanol ethoxylated sulfate, 2,9-dimethyl dodecanol ethoxylated sulfate, 2,10-dimethyl dodecanol ethoxylated sulfate, and mixtures thereof, wherein the compounds are ethoxylated with an average degree of ethoxylation of from about 0.1 to about 10.
(3) Mid-chain Branched Primary Alkyl Polyoxyalkylene Surfactants
The present branched surfactant system for use in the personal cleansing compositions may comprise one or more mid-chain branched primary alkyl polyoxyalkylene surfactants having the formula 
The surfactant mixtures of the present invention comprise molecules having a linear primary polyoxyalkylene chain backbone (i.e., the longest linear carbon chain which includes the alkoxylated carbon atom). These alkyl chain backbones comprise from 10 to 18 carbon atoms; and further the molecules comprise a branched primary alkyl moiety or moieties having at least about 1, but not more than 3, carbon atoms. In addition, the surfactant mixture has an average total number of carbon atoms for the branched primary alkyl moieties within the range of from about 12 to 14.5. Thus, the present invention mixtures comprise at least one polyoxyalkylene compound having a longest linear carbon chain of not less than 9 carbon atoms or more than 17 carbon atoms, and the total number of carbon atoms including branching must be at least 10, and further the average total number of carbon atoms for the branched primary alkyl chains is within the range of from about 12 to 14.5.
For example, a C14 total carbon (in the alkyl chain) primary polyoxyalkylene surfactant having 13 carbon atoms in the backbone must have a methyl branching unit (either R, R1 or R2 is methyl) whereby the total number of carbon atoms in the alkyl moiety is 14.
R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl (preferably hydrogen or C1-C2 alkyl, more preferably hydrogen or methyl, and most preferably methyl), provided R, R1, and R2 are not all hydrogen. Further, when z is 0, at least R or R1 is not hydrogen.
Although for the purposes of the present invention the surfactant systems of the above formula do not include molecules wherein the units R, R1, and R2 are all hydrogen (i.e., linear non-branched primary polyoxyalkylenes), it is to be recognized that the present surfactant systems may still further comprise some amount of linear, non-branched primary polyoxyalkylene. Further, this linear non-branched primary polyoxyalkylene surfactant may be present as the result of the process used to manufacture the surfactant mixture having the requisite mid-chain branched primary polyoxyalkylenes according to the present invention, or for purposes of formulating personal cleansing compositions some amount of linear non-branched primary polyoxyalkylene may be admixed into the final product formulation.
The preferred surfactant system will be present in the personal cleansing composition at preferably at least about 0.5%, more preferably, at least about 1%, even more preferably at least about 2%, even more preferably still at least about 5%, even more preferably still at least about 8%, most preferably at least about 10%, by weight. Furthermore, the preferred surfactant mixture will be present in the personal cleansing composition at preferably at less than about 45%, more preferably less than about 40%, even more preferably less than about 35%, even more preferably less than about 30%, by weight of the mixture one or more branched primary alkyl polyoxyalkylenes having the formula 
wherein the total number of carbon atoms, including branching, is from 10 to 16, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of from about 12 to about 14; R1 and R2 are each independently hydrogen or C1-C3 alkyl; x is from 0 to 10; y is from 0 to 10; z is at least 1; and x+y+z is from 4 to 10; provided R1 and R2 are not both hydrogen; and EO/PO are alkoxy moieties selected from ethoxy, propoxy, and mixed ethoxyipropoxy groups, more preferably ethoxy, wherein m is at least about 1, preferably within the range of from about 3 to about 30, more preferably from about 5 to about 20, and most preferably from about 5 to about 15. More preferred are compositions having at least 5% of the mixture comprising one or more mid-chain branched primary polyoxyalkylenes wherein z is at least 2.
Preferably, the mixtures of surfactant comprise at least 0.1%, preferably at least about 0.5%, of a mid chain branched primary alkyl polyoxyalkylene having R1 and R2 independently hydrogen or methyl, provided R1 and R2 are not both hydrogen; x+y is equal to 5, 6 or 7 and z is at least 1.
Preferred mixtures of mid-chain branched primary alkyl polyoxyalkylene surfactants comprise at least about 5% by weight of one or more mid-chain branched alkyl polyoxyalkylenes having the formula: 
or mixtures thereof; wherein a, b, d, and e are integers, a+b is from 6 to 13, d+e is from 4 to 11 and wherein further
when a+b=6, a is an integer from 2 to 5 and b is an integer from 1 to 4;
when a+b=7, a is an integer from 2 to 6 and b is an integer from 1 to 5;
when a+b=8, a is an integer from 2 to 7 and b is an integer from 1 to 6;
when a+b=9, a is an integer from 2 to 8 and b is an integer from 1 to 7;
when a+b=10, a is an integer from 2 to 9 and b is an integer from 1 to 8;
when a+b=11, a is an integer from 2 to 10 and b is an integer from 1 to 9;
when a+b=12, a is an integer from 2 to 11 and b is an integer from 1 to 10;
when a+b=13, a is an integer from 2 to 12 and b is an integer from 1 to 11;
when d+e=4, d is an integer from 2 to 3 and e is an integer from 1 to 2;
when d+e=5, d is an integer from 2 to 4 and e is an integer from 1 to 3;
when d+e=6, d is an integer from 2 to 5 and e is an integer from 1 to 4;
when d+e=7, d is an integer from 2 to 6 and e is an integer from 1 to 5;
when d+e=8, d is an integer from 2 to 7 and e is an integer from 1 to 6;
when d+e=9, d is an integer from 2 to 8 and e is an integer from 1 to 7;
when d+e=10, d is an integer from 2 to 9 and e is an integer from 1 to 8.
when d+e=11, d is an integer from 2 to 10 and e is an integer from 1 to 9.
and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary all moieties having the above formulas is within the range of from about 12 to 14.5; and EO/PO are alkoxy moieties selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 1, preferably within the range of from about 3 to about 30, more preferably from about 5 to about 20, and most preferably from about 5 to about 15.
Further, the present surfactant system may comprise a mixture of linear and branched surfactants wherein the branched primary alkyl polyoxyalkylene has the formula: 
wherein the total number of carbon atoms per molecule, including branching, is from 10 to 17, and wherein further for this surfactant mixture the average total number of carbon atoms in the branched primary alkyl moieties having the above formula is within the range of about 12 to 14.5; R, R1, and R2 are each independently selected from hydrogen and C1-C3 alkyl, provided R, R1, and R2 are not all hydrogen; M is a water soluble cation; w is an integer from 0 to 10; x is an integer from 0 to 10; y is an integer from 0 to 10; z is an integer from 0 to 10; and w+x+y+z is from 3 to 10; EO/PO are alkoxy moieties, preferably selected from ethoxy, propoxy, and mixed ethoxy/propoxy groups, wherein m is at least about 1, preferably within the range of from about 3 to about 30, more preferably from about 5 to about 20, and most preferably from about 5 to about 15; provided that when R2 is a C1-C3 alkyl the ratio of surfactants having z equal to 1 or greater to surfactants having z of 0 is at least about 1:1, preferably at least about 5:1, more preferably at least about 10:1, and most preferably at least about 20:1. Also preferred are surfactant compositions, when R2 is a C1-C3 alkyl, comprising less than about 20%, preferably less than 10%, more preferably less than 5%, most preferably less than 1%, of branched primary alkyl polyoxyalkylene having the above formula wherein z equals 0.
Preferred mono-methyl branched primary alkyl ethoxylates are selected from the group consisting of: 3-methyl dodecanol ethoxylate, 4-methyl dodecanol ethoxylate, 5-methyl dodecanol ethoxylate, 6-methyl dodecanol ethoxylate, 7-methyl dodecanol ethoxylate, 8-methyl dodecanol ethoxylate, 9-methyl dodecanol ethoxylate, 10-methyl dodecanol ethoxylate, 3-methyl tridecanol ethoxylate, 4-methyl tridecanol ethoxylate, 5-methyl tridecanol ethoxylate, 6-methyl tridecanol ethoxylate, 7-methyl tridecanol ethoxylate, 8-methyl tridecanol ethoxylate, 9-methyl tridecanol ethoxylate, 10-methyl tridecanol ethoxylate, 11-methyl tridecanol ethoxylate, and mixtures thereof, wherein the compounds are ethoxylated with an average degree of ethoxylation of from about 5 to about 15.
Preferred dimethyl branched primary alkyl ethoxylates selected from the group consisting of: 2,3-dimethyl undecanol ethoxylate, 2,4-dimethyl undecanol ethoxylate, 2,5-dimethyl undecanol ethoxylate, 2,6-dimethyl undecanol ethoxylate, 2,7-dimethyl undecanol ethoxylate, 2,8-dimethyl undecanol ethoxylate, 2,9-dimethyl undecanol ethoxylate, 2,3-dimethyl dodecanol ethoxylate, 2,4-dimethyl dodecanol ethoxylate, 2,5-dimethyl dodecanol ethoxylate, 2,6-dimethyl dodecanol ethoxylate, 2,7-dimethyl dodecanol ethoxylate, 2,8-dimethyl dodecanol ethoxylate, 2,9-dimethyl dodecanol ethoxylate, 2,10-dimethyl dodecanol ethoxylate and mixtures thereof, wherein the compounds are ethoxylated with an average degree of ethoxylation of from about 5 to about 15.
Preparation of Mid-chain Branched Surfactants
The following reaction scheme outlines a general approach to the preparation of the mid-chain branched primary alcohol useful for alkoxylating and/or sulfating to prepare the mid-chain branched primary alkyl surfactants of the present invention. 
An alkyl halide is converted to a Grignard reagent and the Grignard is reacted with a haloketone. After conventional acid hydrolysis, acetylation and thermal elimination of acetic acid, an intermediate olefin is produced (not shown in the scheme) which is hydrogenated forthwith using any convenient hydrogenation catalyst such as Pd/C.
This route is favorable over others in that the branch, in this illustration a 5-methyl branch, is introduced early in the reaction sequence.
Formulation of the alkyl halide resulting from the first hydrogenation step yields alcohol product, as shown in the scheme. This can be alkoxylated using standard techniques and/or sulfated using any convenient sulfating agent, e.g., chlorosulfonic acid, SO3/air, or oleum, to yield the final branched primary alkyl surfactant. There is flexibility to extend the branching one additional carbon beyond that which is achieved by a single formulation. Such extension can, for example, be accomplished by reaction with ethylene oxide. See xe2x80x9cOrignard Reactions of Nonumetallic Substancesxe2x80x9d, M. S. Kharasch and O. Reinmuth, Prentice-Hall, N.Y., 1954; J. Org. Chem., J. Cason and W. R. Winans, Vol. 15 (1950), pp 139-147; J. Org. Chem., J. Cason et al., Vol. 13 (1948), pp 239-248; J. Org Chem., J. Cason et al., Vol. 14 (1949), pp 147-154; and J. Org. Chem., J. Cason et al., Vol. 15 (1950), pp 135-138 all of which are incorporated herein by reference.
In variations of the above procedure, alternate haloketones or Grignard reagents may be used. PBr3 halogenation of the alcohol from formulation or ethoxylation can be used to accomplish an iterative chain extension.
The preferred mid-chained branched primary alkyl alkoxylated sulfates (as well as the polyoxyalkylenes and alkyl sulfates, by choosing to only alkoxylate or sulfate the intermediate alcohol produced) of the present invention can also be readily prepared as follows: 
A conventional bromoalcohol is reacted with triphenylphosphine followed by sodiumn hydride, suitably in dimethylsulfoxide/tetrahydrofainr, to form a Wittig adduct. The Wittig adduct is reacted with an alpha methyl ketone, forming an internally unsaturated methyl-branched alcoholate. Hydrogenation followed by alkoxylation and/or sulfation yields the desired mid-chain branched primary alkyl surfactant. Although the Wittig approach does not allow the practitioner to extend the hydrocarbon chain, as in the Grignard sequence, the Wittig typically affords higher yields. See Agricultural and Biological Chemistry, M. Horiike et al., vol. 42 (1978), pp 1963-1965 included herein by reference.
Any alternative synthetic procedure in accordance with the invention may be used to prepare the branched primary alkyl surfactants. The mid-chain branched primary alkyl surfactants may, in addition be synthesized or formulated in the presence of the conventional homologs, for example any of those which may be formed in an industrial process which produces 2-alkyl branching as a result of hydroformylation.
In certain preferred embodiments of the surfactant mixtures of the present invention, especially those derived from fossil fuel sources involving commercial processes, said surfactant mixtures comprise at least 1 mid-chain branched primary alkyl surfactant, preferably at least 2, more preferably at least 5, most preferably at least 8. Particularly suitable for preparation of certain surfactant mixtures of the present invention are xe2x80x9coxoxe2x80x9d reactions wherein a branched chain olefin is subjected to catalytic isomerization and hydroformylation prior to alkoxylation and/or sulfation. The preferred processes resulting in such mixtures utilize fossil fuels as the starting material feedstock. Preferred processes utilize Oxo reaction on olefins (alpha or internal) with a limited amount of branching. Suitable olefins may be made by dimerization of linear alpha or internal olefins, by controlled oligomerization of low molecular weight linear olefins, by skeletal rearrangement of detergent range olefins, by dehydrogenation/skeletal rearrangement of detergent range paraffins, or by Fischer-Tropsch reaction These reactions will in general be controlled to:
1) give a large proportion of olefins in the desired detergent range (while allowing for the addition of a carbon atom in the subsequent Oxo reaction),
2) produce a limited number of branches, preferably mid-chain,
3) produce C1-C3 branches, more preferably ethyl, most preferably methyl,
4) limit or eliminate gem dialkyl branching i.e. to avoid formation of quaternary carbon atoms.
The suitable olefins can undergo Oxo reaction to give primary alcohols either directly or indirectly through the corresponding aldehydes. When an internal olefin is used, an Oxo catalyst is normally used which is capable of prior pre-isomerization of internal olefins primarily to alpha olefins. While a separately catalyzed (i.e. non-Oxo) internal to alpha isomerization could be effected, this is optional. On the other hand, if the olefin-forming step itself results directly in an alpha olefin (e.g. with high pressure Fischer-Tropsch olefins of detergent range), then use of a non-isomerizing Oxo catalyst is not only possible, but preferred.
The process described herein above, with tridecene, gives the more preferred 5-methyl-tridecyl alcohol and therefore surfactants in higher yield than the less preferred 2,4-dimethyldodecyl materials. This mixture is desirable under the metes and bounds of the present invention in that each product comprises a total of 14 carbon atoms with linear alkyl chains having at least 12 carbon atoms.